pV/T Master

pV/T Master ™ - Volumetric Analyzer lab in-one

​The pV/T Master™ is a novel and versatile volumetric analyzer that allows implementation of variety of static and dynamic techniques by using the core instrument and optional or user provided ancillary hardware. As presented, the basic instrument can be used for volume (density) measurements of  any solid state samples and compressibility studies of cellular materials (foams) using gas expansion technique or time domain pycnometry. The open-architecture design allows for using all resources for variety of research activities. 

Design features (basic instrument, as shown):

• Automatic and Manual modes (hardware and software)
• Volume (density) determinations using pressure or vacuum
• Compressibility profiles of foams versus pressure and pressure intervals
• Software controlled miniature vacuum pump (<10 kPa capability)
• Mass flow controller for implementing of dynamic operation
• Precision low pressure regulator for setting repeatable pressure values
• Absolute pressure transducer (typically 50 psia, 340 kPa)
• Hermetically closed sample holders (No elutriation for fine powders)
• (Optional) flow-through sample holders for controlled purge
• Introduction of time-domain pycnometer
• Added ports for usage of analyzer resources 
• Unique software design to create experiments from preprogrammed functionalities
• Extended software features beyond pycnometry for recording data from various experimentation
• Easy interfacing with external hardware to implement additional capabilities
• Availability of additional temperature sensor (RTD, typically -50ºC to 150ºC)

Possible extensions:

•  Non-isothermal measurements using external sample chambers at different temperatures
•  Easy extension of the sample volume range well over 100 mL
• Bubble point technique
• Liquid expulsion porometry
• Gas transfer rates through various barriers, like films, filters
• Flow rates measurements through packed beds of powders
• Gas permeability coefficients, density, and porosity of rock core samples, e.g. sandstones
  
• Testing of thermal degradation of plastic materials
• Moisture content analyzer - dynamic water vapor desorption at various temperatures and flow rates using RH probe for water mass measurements
• Headspace extraction at controlled temperatures using either closed system or  flow-through mode (dry gas or  humidified gas from external RH generator)
• Surface area analyzers, e.g. by flow through packed beds of powder – permeability technique or physical sorption using cryogenic

​           temperatures within the transducer pressure range (0 - 340 kPa)

Foam Compressibility  vs Pressure / Vacuum

P=220 kPa

P=101 kPa

P=7 kPa

Application notes (pdf):

1. Volume changes of compressible materials versus pressure intervals  and foam characterization by a density profile instead of a single value using pV/T Master, a versatile volumetric analyzer.                                               

​In general, density of compressible (cellular) materials cannot be described by a single number but rather by a range of values. This technical note presents a new instrumental and methodological approach for studying materials that can change their volume versus pressure, like easily compressible foams with closed cells.  

2. Time-domain pycnometry and addition of dynamic mode of operation to gas expansion pycnometer.      

​Combining dynamic (flow type) and static (gas expansion) modes in one instrument forms a highly capable and novel gas (helium) pycnometer. This technical note presents overview of a new instrumental and methodological approach for materials characterization as well as other possible applications of this volumetric analyzer.  

pV/T Master with optional Permeability Cell Station

3. Measurement of specific surface area of powders using new method and instrumentation

​Absolute method of determination of specific surface area of powders is being proposed. Development of a versatile volumetric analyzer, pV/T Master, and ancillary hardware allows for carrying out all measurements using one instrument. Better implementation of the permeametry technique can make it more effective in characterization of powders.

​Deviations from linearity of pressure versus added volume profile as a measure of foam compressibility and its thermal degradation

4. Testing of compressible materials and their thermal degradation using time-domain mode of the volumetric analyzer pV/T Master™ and external temperature-controlled chamber                                     

​Addition of a separate thermally controlled chamber to the pV/T Master volumetric analyzer allows for enhanced characterization of materials in the temperature range from just above zero ºC to over 100 ºC.  This technical note presents a new instrumental and methodological approach for studying materials that can change their properties versus temperature and pressure, e.g. foams.

Moisture loss on drying at various temperatures

5. ​Implementation of flow-based moisture desorption method using volumetric analyzer pV/T Master™ and external temperature-controlled chamber

​A  practical method for determination of mass loss of water and prediction of water content beyond the used temperature range is proposed. Using RH probe ensures selectivity towards water vapor instead of the total amount of gas/vapors loss like in gravimetric dynamic water vapor sorption analyzers.  In addition to determining the mass of water loss, using either dry or humidified gas at various temperatures, the extracted volatiles can be delivered to other analytical devices. 

Bubble Point and Capillary Flow Porometer Station

​6. Bubble Point and Capillary Flow Porometer

​Better implementation of the Bubble Point and Capillary Flow Porometer techniques are presented as optional capabilities that can be implemented in the pV/T Master volumetric analyzer.  Improved theoretical approach and critical remarks that are often omitted in commercial marketing of such products are also presented. 

To inquire about our products, please contact us at:  [email protected]    

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INSTRUQUEST INC.  SCIENTIFIC INSTRUMENTS R&D